The invention relates to a method of manufacturing a diffuse reflector in which a surface pattern is provided in a synthetic resin layer.
The invention also relates to a diffuse reflector obtained by such a method.
Diffuse reflectors are notably used in flat display devices such as liquid crystal display devices (LCDs) and electroscopic display devices, but other uses are also known.
A method of the type described in the opening paragraph is described in European Application No. 0,084,930, laid open to public inspection, in which a diffusely reflecting metal surface is provided in a liquid crystal display device by providing a thin layer of reflecting material on a resin layer having projections and recesses. The projections and recesses are provided in advance in the resin layer by means of photolithographic techniques using a photomask, with a second resin layer functioning as a photoresist. Such a method requires inter alia the desired masking step and an etching step in order to realize a surface structure, after which the second layer is removed.
British Patent Specification GB 2,066,545A describes another method of manufacturing diffuse reflectors. In this method a metal film is reactively deposited by means of vapour-deposition techniques or sputtering while adding a small quantity of water. A drawback of this reactive deposition with water (or oxygen) is, however, that the composition of the mixture to be used is very critical during the reaction. Upon deposition, hydroxides or oxides may also be formed, which may considerably reduce the light dispersion.